Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion. Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules. |
14th December 2005, 02:43 | #1 | Link |
John Weathers
Join Date: Nov 2005
Location: Atlanta, GA
Posts: 27
|
Remove or prevent delays during AC3 Encoding?
I am in the process of inserting some deleted scenes back into Attack of the Clones. I have successfully edited the video, but I am having some trouble with the audio portion.
Specifically, I have ripped the soundtrack and the deleted scene soundtracks into AC3 files. I then used BeSplit to split up the soundtrack into chunks including small neighborhoods around areas where I need to create sound transisitions. I then decoded these neighborhoods into groups of 6 Mono WAVs. After making my transitions successfully, I then reencode the neighborhoods that I had previously decoded with the intention of then joining everything back together into one big AC3. This way the loss of quality from reencoding is limited to small 2 - 4 second windows around the transitions. Unfortunately, Softencode seems to add a small bit of silence at the beginning of each AC3 that it produces. While the silence is really small and unnoticeable if you just play it in isolation, it is very noticeable when joined back into the soundtrack. Is there some way to eliminate these delays using Softencode or another encoder? The BeSweet encoder seems to barely add any delay if at all, but it has the problem that the volume seems to be cut in half and the sound wave seems inverted as well. I would rather not reencode the entire soundtrack as I am trying to preserve as much quality as possible. However, even when I tried doing this, I noticed that BeSweet complained about overflow issues when trying to decode the entire soundtrack which doesn't look good... Any help or advice would be greatly appreciated! |
14th December 2005, 14:29 | #2 | Link |
Registered User
Join Date: Sep 2005
Posts: 19
|
Hi
You should be able to encode your waves to ac3 using besweet, the way I do it is create a list.mux then load that into besweet using BeSweetGUI v0.7 b4 I have a test file you can try all you need to do is drop it straight on C drive and open the mux file with besweet, the ac3 file created is a channel test for each speaker so you Know the order is right. Then all your need to do is edit the paths in the mux file with note pad for your waves when you want to encode them. You can get the file here http://www.savefile.com/files.php?fid=2231546 XIII Last edited by XIII; 14th December 2005 at 14:41. |
15th December 2005, 03:18 | #3 | Link | |
John Weathers
Join Date: Nov 2005
Location: Atlanta, GA
Posts: 27
|
Quote:
The problem with this approach however is that when I examine the AC3 files created by BeSweet by decoding them into WAV files, it becomes apparent that BeSweet's encoder (ac3enc) not only cuts the volume nearly in half, but strangely it seems to invert the WAV. The first issue seems to be a known problem with no fix in sight. The second is just bizarre. Thus, ac3enc seems unacceptable unless I can get around these two issues. That is why I was using Softencode. However, it introduces these delays at the beginning. That is why my question is whether it is possible to remove or prevent these delays. It doesn't look like there is option that could effect this in Softencode, but I wanted to make sure or see if people have found alternative ways of dealing with this issue. |
|
15th December 2005, 14:45 | #4 | Link |
Registered User
Join Date: Sep 2005
Posts: 19
|
Hi
Volume is easily solved by using the Boost in besweet. I added the link to the file because you said the wav file gets inverted which it doesn't do when I use that mux file in that order. If you can get your hands on "Sony Vegas+DVD Architect" you can use that to encode your wav files to ac3. Other than that there are loads of programs to add or remove a silence from the beginning of an ac3 file. XIII |
15th December 2005, 17:57 | #5 | Link | |||
John Weathers
Join Date: Nov 2005
Location: Atlanta, GA
Posts: 27
|
Quote:
Quote:
Quote:
|
|||
15th December 2005, 19:13 | #6 | Link |
Moderator
Join Date: Feb 2005
Location: Spain
Posts: 6,915
|
In my test with SoftEncode the delay is only 5.333 ms.
I try to add 26.667 ms at the beginning of wav, an after cut the first 32 ms frame (with DelayCut, or with WinHex), the sync is recovered but still remain this time (about 5 ms) until the wav reaches the 100% volume, and can produce audible click. The same results with Headac3he (+6Db). With BeSweet same delay, half volume and inverted wav. |
16th December 2005, 16:21 | #7 | Link |
Registered User
Join Date: Sep 2005
Posts: 19
|
Hi
The only real way to get the right dB when using boost is to have a small audio clip of the source wav's say a minute long and test it, takes a few seconds at most. Besweet its self allows you to add or remove a silence, or there's a small app called " AC3 Delay Corrector " DVD lab pro can also do this. Strange I have used many methods to encode from wav to ac3 and have never had any of the above. I will say though Softencode was by far the worst. XIII |
|
|